Wednesday, February 12, 2014

Aeon trashes quantum interpretations

The Copenhagen interpretation was very much in line with the scientific philosophy of logical positivism that caught on at around the same time. In particular, it rests on something like logical positivism’s principle of verification, according to which a scientific statement is meaningful only if we have some means of verifying its truth. To some of the founders of quantum theory, as well as to later adherents of the Copenhagen interpretation, this came to seem an almost self-evident description of the scientific process. Even after philosophers largely abandoned logical positivism – not least because the principle of verification fails its own test for meaningful statements – many physicists trained in the Copenhagen tradition insisted that their stance was no more than common sense.

However, its consequences are far from commonsensical. If you take this position seriously, then you have to accept that the Higgs boson wasn’t actually discovered at the Large Hadron Collider, since no one has ever directly detected a Higgs boson, and we have no direct evidence to support the claim that the Higgs boson is a real particle. Insofar as we learnt anything about nature from the Large Hadron Collider, it was merely what sort of records you get in your detectors when you build something like the Large Hadron Collider. It’s hard to imagine the scientists who work on it, or the citizens who funded them, being very enthusiastic about this justification, but on a strict Copenhagen view it’s the best we can do.

This starts out reasonable, and then descends into gibberish. Yes it is true that logical positivists and the founders of quantum mechanic were following a self-evident description of the scientific process.

It is also true that philosophers abandoned logical positivism, and along with it they abandoned scientific objectivity and progress towards truth. It is not true that logical postivism fails its own test.

But then the paragraph about the Higgs boson is nonsense. You could say that the Higgs was not detected directly, but you could say the same about electrons and photons. Quantum mechanics teaches that there is no such thing as a real particle, in the classical sense. There are fields and waves that have particle properties in certain observations. The only difference with the Higgs is that a lot of other particles are detected at the same time, so finding the Higgs is technically very difficult. But it is still an observation, just like all the others in the Copenhagen.

After attacking Copenhagen, the article moves on to other interpretations but finds them unsatisfactory also.

If we cannot get a coherent story about physical reality from the Copenhagen interpretation of quantum theory and we cannot get a scientifically adequate one from many-worlds theory, where do we turn? We could, as some physicists suggest, simply give up on the hope of finding any description of an objective external reality. But it is very hard to see how to do this without also giving up on science. ...

Bell was one of the last century’s deepest thinkers about science. As he put it, quantum theory ‘carries in itself the seeds of its own destruction’: it undermines the account of reality that it needs in order to make any sense as a physical theory. On this view, which was once as close to heresy as a scientific argument can be but is now widely held among scientists who work on the foundations of physics, the reality problem is just not solvable within quantum theory as it stands.

The problem here is that philosophers, Bell, Einstein, and physicists working on quantum foundations have abandoned scientific common sense in favor of a 19th century view of science. The founders of quantum mechanics thought that science was all about observation, and were happy with the theory. They have been replaced by fools who think science is all about postulating unobservable multiverses, hidden variables, and other fictions.